Hello
It can be done by MySQL query in the database. The domain list is defined in the table "domains", the scheduled backup options are stored in the table BackupsScheduled. See the query to get the listing of all domains with scheduled backups:
mysql> select domains.name, domains.id, BackupsScheduled.obj_id, BackupsScheduled.last from domains, BackupsScheduled where domains.id=BackupsScheduled.obj_id;
Also, it is possible to run it at once from command line:
mysql -uadmin -p`cat /etc/psa/.psa.shadow` psa -e"select domains.name, domains.id, BackupsScheduled.obj_id, BackupsScheduled.last from domains, BackupsScheduled where domains.id=BackupsScheduled.obj_id;"